1. Field of the Invention
The invention presented herein relates to electro-optical feedback signal producing apparatus for use in a control apparatus.
2. Discussion of the Prior Art
Positional accuracy and response speed in placing an object such as a scanning mirror at a desired location has been difficult to attain for any reasonable cost. Difficulty has been encountered in obtaining a signal indicative of the actual position of the object for use as a feedback signal. Open-loop mirror systems which use a galvanometer as the drive mechanism are available to which a velocity feedback coil is added to speed up the transient response. Positional accuracy and response speed are poor, however. A scanning mirror utilizing capacitance feedback is available, but is very costly.